JP2021160879A - Sheet processing device and image formation system - Google Patents

Abstract

To suppress the deviation and collapse of a first folding position when executing plural times of folding processing to a sheet.SOLUTION: The first folding processing is performed by a rotor pair 22 to a sheet conveyed by a conveyance path 20. The folded sheet subjected to the first folding processing is returned to the conveyance path. When the second folding processing is performed by the rotor pair to the folded sheet returned to the conveyance path, in a case where the first folding position E3 where the first folding processing is performed in the sheet passes through a nip part 22c of the rotor following the second folding processing, the pressing force to the first folding position by the rotor pair is adjusted to be lower than the time when the first folding processing is performed.SELECTED DRAWING: Figure 15

Description

The present invention relates to, for example, a sheet processing device for folding a sheet sent from an image forming device and an image forming system including the same.

Conventionally, as a post-processing of sheets discharged from an image forming apparatus such as a copier, a printer, a facsimile, or a composite device thereof, a sheet processing apparatus for folding a bundle of sheets into a booklet has been provided. For example, a sheet processing device is known in which a predetermined position of a sheet carried out from an image forming apparatus to a sheet stacker is bent by a veneer and pushed into a nip portion of a pair of folding rollers, and the sheet is folded in half while being conveyed by the pair of folding rollers. There is.

In the sheet processing device that folds the sheet, not only the sheet is folded in half, but also two different parts of the sheet are folded so that one end of the sheet is inside the folded sheet. There is a sheet processing device that executes the inner tri-fold processing. In such a device, the sheet that has been folded the first time is transferred back to the stacker and returned to the stacker, and the second folding process is executed on this sheet at a position different from the first time, so that the sheet is folded in three. (Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-56674

However, in the sheet folding device described in Patent Document 1, when the sheet is folded at the first folding position and then switched back to the transport path to return the sheet, and at the second folding position. When the sheet is ejected after the folding process, the first folding position of the folded sheet passes again between the folding rollers that are in pressure contact with each other. Therefore, a crease is made again with respect to the first fold position. At this time, if the second crease deviates from the first crease, the crease may deviate, the crease may collapse, or wrinkles may occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is a sheet processing capable of suppressing the first folding position from being displaced or collapsed when a plurality of folding processes are executed. It provides an apparatus and an image forming system equipped with the apparatus.

A typical configuration according to the present invention for achieving the above object is to perform a first folding process on a sheet, and then perform a second folding process at a position different from the crease formed by the first folding process. In a sheet processing device that performs a folding process so that one end of the sheet folded by the first folding process is inside the folded sheet, a transport path for guiding the sheet to be transported. , A positioning means for positioning the sheet transported to the transport path in the transport path, and a rotation for folding the sheet by pressing the sheet transported to the transport path with a nip and rotating the sheet. The body pair, the protruding member that projects the sheet conveyed to the transport path toward the nip portion of the rotating body pair, the first direction in which the sheet folded by the rotating body pair is pulled in, and the first direction. The transport means capable of transporting the sheet by switching back in the second direction opposite to the direction, the pressing adjusting means for adjusting the pressing force at the nip portion of the pair of rotating bodies, and the sheet conveyed to the transport path. The first folding process is performed by the pair of rotating bodies, the folded sheet that has undergone the first folding process is returned to the transport path, and the folded sheet that has been returned to the transport path is returned to the transport path by the pair of rotating bodies. When the second folding process is performed, when the first folding position of the sheet subjected to the first folding process passes through the nip portion of the rotating body following the second folding process, the said In order to reduce the pressing force of the pair of rotating bodies to the first folding position compared to when the first folding process is performed, the positioning means, the pair of rotating bodies, the protruding member, and the conveying means. And a control unit for controlling the pressing adjusting means.

In the present invention, the first folding position of the sheet that has been folded by passing through the nip portion of the pair of rotating bodies is displaced or collapsed due to passing through the nip portion of the pair of rotating bodies again. Occurrence can be suppressed.

Explanatory drawing of the whole structure of the image formation system of this embodiment Explanatory drawing of the whole composition of the sheet processing apparatus in an image formation system Sectional drawing which shows the folding processing apparatus of a sheet processing apparatus Top view showing the sheet folding processing apparatus Block diagram of folding control configuration Flowchart showing the inner tri-fold processing procedure Flowchart showing the inner tri-fold processing procedure Flowchart showing the inner tri-fold processing procedure (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. (A) and (b) are cross-sectional explanatory views of the inner tri-folding operation of the sheet. Cross-sectional explanatory view of the inner tri-folding operation of the sheet Explanatory drawing of separation mechanism of folding roller pair

[First Embodiment]
Next, a sheet processing apparatus according to a preferred embodiment of the present invention and an image forming system including the sheet processing apparatus will be described with reference to the drawings. FIG. 1 schematically shows an overall configuration of an image forming system including a sheet processing apparatus according to an embodiment of the present invention. As shown in the figure, the image forming system 100 includes an image forming apparatus A and a sheet processing apparatus B attached thereto.

<Overall configuration of image forming device>
The image forming apparatus A includes an image forming unit A1, a scanner unit A2, and a feeder unit A3. The image forming unit A1 includes a feeding unit 2, an image forming unit 3, an discharging unit 4, and a data processing unit 5 inside the device housing 1.

The feeding unit 2 is composed of a plurality of cassette mechanisms 2a, 2b, 2c for accommodating image forming sheets of different sizes, and feeds a sheet of a size specified by a main body control unit (not shown) to the feeding path 2f. Each of the cassette mechanisms 2a, 2b, and 2c is detachably installed from the feeding unit 2, and has a built-in separation mechanism for separating the internal sheets one by one and a feeding mechanism for feeding out the sheets. The feeding path 2f is provided with a transport roller that feeds the sheets supplied from the cassette mechanisms 2a, 2b, and 2c to the downstream side, and a registration roller pair that aligns the tips of the sheets at the end of the path. ing.

A large-capacity cassette 2d and a manual feed tray 2e are connected to the feed path 2f. The large-capacity cassette 2d is composed of an optional unit that stores a sheet of a size that is consumed in large quantities. The manual feed tray 2e is configured to be able to supply special sheets such as thick paper sheets, coating sheets, and film sheets that are difficult to separately feed.

In the present embodiment, the image forming unit 3 is configured by using an electrophotographic method, and includes a rotating photosensitive drum 3a, a light emitter 3b, a developing device 3c, and a cleaner (a light emitter 3b, a developing device 3c, and a cleaner, which are arranged around the rotating photosensitive drum 3a and emit an optical beam. (Not shown). The one shown in the figure is a monochrome printing mechanism, in which a photosensitive drum 3a whose peripheral surface is uniformly charged is irradiated with light according to an image signal by a light emitter 3b to optically form a latent image, and the latent image is developed. A toner image is formed by adhering toner with the vessel 3c.

A sheet is sent to the image forming unit 3 from the feeding path 2f at the timing of forming an image on the photosensitive drum 3a, and a toner image formed on the photosensitive drum 3a is transmitted on the sheet by applying a transfer bias from the transfer charger 3d. Transfer to. The sheet on which the toner image is transferred is heated and pressurized when passing through the fixing device 6, the toner image is fixed, and the sheet is discharged from the discharge port 4b by the discharge roller 4a and conveyed to the sheet processing device B described later. ..

The scanner unit A2 photoelectrically converts the platen 7a on which the image document is placed, the carriage 7b reciprocating along the platen 7a, the photoelectric conversion means 7c, and the light reflected from the document on the platen 7a by the carriage 7b. It is provided with a reduction optical system 7d that guides the means 7c. The photoelectric conversion means 7c photoelectrically converts the optical output from the reduction optical system 7d into image data and outputs it as an electric signal to the image forming unit 3.

Further, the scanner unit A2 is provided with a traveling platen 7e for reading the sheet sent from the feeder unit A3. The feeder unit A3 stores a feed tray 8a for loading the document sheet, a feed path 8b for guiding the document sheet sent out from the feed tray 8a to the traveling platen 7e, and a document sheet passing through the traveling platen 7e. It is composed of a discharge tray 8c. The document sheet from the feed tray 8a is read by the carriage 7b and the reduction optical system 7d when passing through the traveling platen 7e.

<Overall configuration of sheet processing equipment>
Next, the overall configuration of the sheet processing device B that post-processes the sheet sent from the image forming device A will be described.

FIG. 2 is a configuration explanatory view of the sheet processing device B according to the present embodiment. The sheet processing device B includes a device housing 11 provided with a carry-in port 10 for introducing a sheet from the image forming device A. The device housing 11 is aligned with the housing 1 of the image forming apparatus A so that the carry-in inlet 10 communicates with the discharge port 4b of the image forming apparatus A.

The sheet processing device B includes a sheet carry-in path 12 for transporting sheets introduced from the carry-in port 10, a first discharge path 13a, a second discharge path 13b, and a third discharge path 13c branched from the sheet carry-in path 12. A first path switching means 14a and a second path switching means 14b are provided. The first route switching means 14a and the second route switching means 14b are each composed of flapper guides that change the transport direction of the sheets transported along the sheet carry-in route 12.

The first path switching means 14a has a mode of guiding the sheet from the carry-in inlet 10 in the lateral direction as it is in the direction of the first discharge path 13a and the second discharge path 13b which conveys the sheet downward by a drive means (not shown). The mode is switched to the mode of guiding to the third discharge path 13c to be conveyed upward. The first discharge path 13a and the second discharge path 13b communicate with each other so that the sheet once introduced in the first discharge path 13a can be switched back to the second discharge path 13b by reversing the transport direction. doing.

The second route switching means 14b is arranged on the downstream side of the first route switching means 14a with respect to the transport direction of the sheet transported along the sheet carry-in route 12. The second path switching means 14b has a mode in which a sheet that has passed through the first path switching means 14a is introduced into the first discharge path 13a and a sheet that has been once introduced into the first discharge path 13a by a drive means (not shown). 2 Switch back to the discharge path 13b.

The sheet processing device B includes a first processing unit B1, a second processing unit B2, and a third processing unit B3 that perform different post-processing. Further, a punch unit 15 for punching a punch hole in the carried-in sheet is arranged in the sheet carry-in route 12.

The first processing unit B1 collects a plurality of sheets carried out from the discharge port 16a at the downstream end of the first discharge path 13a with respect to the transport direction of the sheets transported through the sheet carry-in path 12, aligns the sheets, and performs the binding process. It is a binding processing unit that discharges to the loading tray 16b provided on the outside of the device housing 11. Further, the first processing unit B1 includes a sheet conveying device 16c for conveying a sheet or a sheet bundle, and a binding processing unit 16d for binding the sheet bundle. At the downstream end of the first discharge path 13a, a discharge roller pair 16e is provided for discharging the sheet from the discharge port 16a and for switching back from the first discharge path 13a to the second discharge path 13b.

The second processing unit B2 is a folding processing unit that forms a plurality of sheets transported by switchback from the second discharge path 13b into a sheet bundle, binds the sheet bundle, and then performs a folding process. As will be described later, the second processing unit B2 includes a folding processing device F for folding the carried-in sheet or the sheet bundle, and the folding processing device F along the sheet transporting direction of the sheet transported to the second discharge path 13b. It is provided on the immediately upstream side of F and includes a binding processing unit 17a for binding a bundle of sheets. The folded sheet bundle is discharged to the loading tray 17c provided on the outside of the device housing 11 by the discharge roller 17b.

The third processing unit B3 divides the sheets sent from the third discharge path 13c into a group in which sheets are collected by offsetting a predetermined amount in the sheet width direction orthogonal to the transport direction and a group in which sheets are collected without offsetting. Perform jog sorting. The jog-sorted sheets are discharged to a loading tray 18 provided on the outside of the device housing 11, and an offset sheet bundle and a non-offset sheet bundle are stacked.

FIG. 3 schematically shows the overall configuration of the second processing unit B2. As described above, the second processing unit B2 binds the sheet bundle before the folding process and the folding processing device F that carries in the sheet bundle from the second discharge path 13b and folds the sheet bundle that has been accumulated and aligned in half. A binding processing unit 17a for processing is provided. The binding processing unit 17a shown in the drawing is a stapler device for binding a bundle of sheets by driving a staple.

A sheet transport path 20 is connected to the second discharge path 13b in order to carry the sheet into the folding processing device F. Regarding the transport direction of the sheets transported from the second discharge path 13b to the sheet loading tray 21, the sheet loading tray 21 forming a part of the sheet transport path 20 is folded on the downstream side of the sheet transport path 20. Is provided for positioning and loading. Immediately upstream of the sheet loading tray 21, a binding processing unit 17a and a needle receiving portion 17d thereof are provided at opposite positions with the sheet transport path 20 interposed therebetween.

On one side of the sheet loading tray 21, a folding roller pair 22 as a folding rotating body pair is arranged so as to face one surface of a sheet or a sheet bundle loaded on the sheet loading tray. The folding roller pair 22 is composed of a pair of folding rollers 22a and 22b whose roller surfaces are pressed against each other, and a nip portion 22c which is a pressing portion thereof is arranged toward the seat loading tray 21. The folding rollers 22a and 22b are substantially equal in distance from the seat loading tray 21 on the upstream side and the downstream side along the transport direction of the sheets transported from the upstream side above to the downstream side below the sheet loading tray 21. And juxtaposed. In the present invention, the rotating portion of the folding rotating body pair is not limited to the folding rollers 22a and 22b of the present embodiment, and may be configured by a rotating belt or the like. Further, the folding roller pair 22 can be configured by continuously arranging a plurality of folding rollers (rotating bodies) in series along the axial direction of each of the folding rollers 22a and 22b.

As shown in FIG. 3, each of the folding rollers 22a and 22b of the folding roller pair 22 of the present embodiment has a radius R1 of which the peripheral surfaces of the rollers are constant about the rotation axis of the rotation shafts 22a1, 22b1. It has one roller surface 22a2 and 22b2, and second roller surfaces 22a3 and 22b3 whose distance from the center of rotation of the rotating shaft is smaller than the radius R1 of the first roller surface. The first roller surfaces 22a2 and 22b2 are formed of a rubber material or the like having a relatively high coefficient of friction, similar to the roller surfaces of rollers used for ordinary sheet transportation or the like. On the other hand, the second roller surfaces 22a3 and 22b3 are formed of a plastic resin material or the like having a friction coefficient smaller than that of the first roller surfaces 22a2 and 22b2.

The rotating shafts 22a1, 22b1 of the folding rollers 22a and 22b are rotationally driven by a driving means such as a common drive motor. As a result, the rotational positions of the first roller surfaces 22a2 and 22b2 and the second roller surfaces 22a3 and 22b3 can always be synchronized with each other.

A folding blade 23 as a protruding member is arranged on the opposite side of the folding roller pair 22 with the sheet loading tray 21 sandwiched between them. The folding blade 23 is supported on the blade carrier 24 with its tip directed toward the nip portion 22c of the folding roller pair 22. The blade carrier 24 is oriented so as to cross the sheet loading tray 21 at a substantially right angle by a moving means composed of a cam member or the like, that is, a direction that intersects the conveying direction of the sheet conveyed from the second discharge path 13b to the sheet loading tray 21. It is provided so that it can run.

A cam member 25 composed of a pair of mirror-symmetrical eccentric cams on both sides of the blade carrier 24 in the front-rear direction in FIG. 3, that is, in the axial direction of the folding roller (only one is shown in the figure). Are provided at opposite positions. The cam member 25 is rotated around a rotation shaft 25a provided at its eccentric position by a drive means such as a drive motor. The cam member 25 is formed with a cam groove 25b along the outer peripheral edge thereof.

The blade carrier 24 is provided with a cam pin 24c that is slidably fitted in the cam groove 25b as a cam follower.

When the cam member 25 is rotated by the drive motor, the blade carrier 24 reciprocates in a direction that approaches or separates from the seat loading tray 21. As a result, as shown in FIG. 3, the tip of the folding blade 23 is sandwiched between the initial position, which is the position where the tip of the folding blade 23 does not enter the sheet transport path formed by the sheet loading tray 21, and the nip portion 22c of the folding roller pair 22. The folding blade 23 can be linearly moved back and forth along the protrusion path connecting the two positions with and from the maximum protrusion position.

At the lower end of the sheet loading tray 21, a regulation stopper 26 is arranged as a positioning means for positioning the sheet in the sheet transport path by abutting the tip of the transported sheet in the transport direction to regulate the sheet. The regulation stopper 26 is provided so as to be able to be raised and lowered along the seat loading tray 21 by the seat raising and lowering mechanism 27.

The seat elevating mechanism 27 of the present embodiment is a blade carrier when the tip of the folding blade 23 is in the initial position on the back side of the seat loading tray 21 at a position where the tip of the folding blade 23 does not enter the seat transport path formed by the seat loading tray 21. It is a conveyor belt mechanism composed of a pair of pulleys 27a and 27b arranged below the 24 and near the upper and lower ends thereof along the seat loading tray, and a transmission belt 27c wound around both pulleys. .. The regulation stopper 26 is fixed on the transmission belt 27c. By rotating the pulley 27a or 27b on the drive side by a drive means such as a drive motor, the regulation stopper 26 moves up and down between the lower end position shown in FIG. 3 and the desired height position, whereby the seat loading tray 21 The sheet or bundle of sheets can be moved along and positioned at the desired height.

A paddle member 80 capable of contacting the sheet to be conveyed to the sheet loading tray 21 is provided in the middle of the sheet loading tray 21 in the sheet conveying direction. The paddle member 80 is rotatably attached with an elastically deformable rubber plate, and when the sheet is conveyed below the sheet loading tray 21, the paddle member 80 is rotated to pull the sheet downward. , The tip of the sheet in the transport direction is reliably fed to the position regulated by the sheet loading tray 21.

Further, the folding processing device F of the present embodiment further includes a seat side alignment mechanism for aligning and aligning the side portions of the sheets carried into the sheet loading tray 21. As shown in FIG. 4, this sheet side matching mechanism is a pair of seat side matching members 28a, 28b symmetrically arranged on both sides of the sheet loading tray 21 in the sheet width direction (direction orthogonal to the sheet transport direction). Have. Note that FIG. 4 is a schematic plan view of the folding processing device F as viewed from above. The seat side matching members 28a and 28b are movably held so as to be relatively close to each other in the seat width direction. By moving the sheet side matching members 28a and 28b with respect to the sheet transported to the sheet loading tray 21 and whose tip abuts on the regulation stopper 26, the positions of the sheets in the width direction are aligned.

<Pressure adjustment means>
As described above, the folded sheet is pressed by passing through the nip portion 22c of the folding roller pair 22 to perform the folding process. However, the sheet processing apparatus of the present embodiment has the folding rollers 22a and 22b as described above. By providing the first roller surfaces 22a2 and 22b2 and the second roller surfaces 22a3 and 22b3 having a smaller turning radius, the pressing force on the sheet passing through the nip portion 22c can be made different. ..

That is, the folding rollers 22a and 22b are configured to rotate synchronously so that the first roller surfaces 22a2 and 22b2 and the second roller surfaces 22a3 and 22b3 face each other. When the first roller surfaces 22a2 and 22b2 face each other, the nip portion 22c is in pressure contact with a predetermined pressing force, and the sheet S is creases when the sheet S folded in half passes through the nip portion 22c. .. On the other hand, when the second roller surfaces 22a3 and 22b3 face each other, the nip portion 22c is configured to have a slight gap without abutting. Therefore, when the second roller surfaces 22a3 and 22b3 face each other, no pressing force is applied to the sheet passing through the nip portion 22c, and the folding process is not executed.

As described above, the folding roller pair 22 of the present embodiment applies a predetermined pressing force to the sheet passing through the nip portion 22c to perform the folding process, and lowers the pressing force than when performing the folding process. It is possible to adjust so that the seat can pass through in the state of being closed.

<Control unit>
Next, the control configuration of the drive system when folding the seat will be described. As shown in the block diagram of FIG. 5, the control unit 60 inputs detection signals and various processing signals from various detection sensors, and controls driving of various drive motors and the like according to the input signals. For example, the regulation stopper HP sensor 61 that detects whether or not the regulation stopper 26 is in the home position, the folding blade HP sensor 62 that detects whether or not the folding blade 23 is in the home position, and the roller rotation of the folding rollers 22a and 22b. From the folding roller HP sensor 63 that detects whether or not the position is in the set home position position, the pressing guide HP sensor 64 that detects whether or not the pressing guide member 30 (see FIG. 6) described later is in the home position position, and the like. Input the detection signal of.

Then, the control unit 60 operates the regulation stopper motor 65 and the blade carrier 24 that drive the seat lifting mechanism 27 that raises and lowers the regulation stopper 26 so as to follow the procedure of the flowchart shown in FIGS. 6 to 8 according to the input signal. The cam motor 66 that drives the cam member 25 for the purpose and the folding roller motor 67 that drives and rotates the folding roller pair 22 are driven and controlled. Further, the control unit 60 drives a discharge roller motor 68 that drives and rotates the discharge roller 17b that serves as a sheet transporting means, a pressing guide motor 69 for operating the pressing guide member 30, and a paddle motor 70 that drives and rotates the paddle member 80. Control.

<Tri-fold processing operation>
6 to 8 are flowcharts showing an operation procedure of each member when the sheet conveyed to the sheet loading tray 21 is internally folded in three by the folding processing device F. The inner tri-folding process is the first folding process when the sheet is folded in half by the first folding process and the second folding process is performed on the sheet at a position different from the first folding position. This is a process of folding in three so that one end of the sheet folded by the sheet is folded inside the sheet to be folded by the second folding process.

In the folding processing device F of the present embodiment, when the inner tri-folding process is executed, the seat S is folded by passing through the nip portion 22c of the folding roller pair 22 by the first folding process (the first folding process). The folding position of 1) is set so that the pressing force applied when passing through the nip portion 22c of the folding roller pair 22 following the second folding process is lower than that when the first folding process is performed. ..

The following describes the operation when the inner tri-folding process is performed by the folding processing device F of the present embodiment, the flowcharts of FIGS. 6 to 8 and the movement of each part along the flow of the sheet S when the inner tri-folding process is executed. This will be described with reference to the schematic cross-sectional views of FIGS. 9 to 16 shown.

As shown in FIG. 9A, the sheet loading tray 21 of the present embodiment is formed so as to be inclined with respect to the vertical direction, and the sheet S has a guide surface 21a having one surface forming the sheet loading tray 21. While being guided, the seat tip E1 is lowered and the seat rear end E2 is raised so as to fall, and the seat tip E1 is abutted against the regulation stopper 26 to stop. At this time, the position of the regulation stopper 26 is arranged so that the first folding position with respect to the seat S to which the seat tip E1 is abutted is a position facing the folding blade 23. The folding blade 23 is arranged at a position where the seat S protrudes from the side of the guide surface 21a of the seat loading tray 21 toward the folding roller pair 22. In other words, the guide surface 21a of the seat loading tray 21 and the folding roller pair 22 are arranged so as to be in corresponding positions with the seat S interposed therebetween.

When the folding process is executed, as shown in FIG. 9B, the cam motor is driven to move the blade carrier 24 in the direction of the folding roller pair 22, and the folding blade 23 is in the first folding position of the sheet S. It abuts and protrudes into the nip portion 22c (S1). At the same time, the folding roller motor 61 and the discharging roller motor 62 are driven to drive the folding roller pair 22 and the discharging roller 17b in the forward rotation (S2). When a pulse motor is used for each of the motors, when the motor is driven, the number of driven pulses is counted by the counter. When a DC motor is used for each of the motors, the sensor reads the slits of the chord wheel (slit plate) mounted on the rotation shaft of the motor, and the number is counted by the counter.

When the folding blade 23 projects a predetermined amount of protrusion of the first folding portion of the seat S to the nip portion 22c of the folding roller vs. 22 due to the rotation of the cam member 25, the traveling direction is reversed and the folding blade 23 moves in the returning direction to the home position. And return (S3).

As shown in FIG. 9B, due to the protrusion of the folding blade 23, the sheet S protruding to the nip portion 22c where the first roller surfaces 22a2 and 22b2 of the folding roller pair 22 are in pressure contact with each other is sandwiched and conveyed by the folding roller pair 22. During this period, the folding process is performed by pressing with a predetermined pressing force, and the folding process is carried out as it is by the discharging roller 17b constituting the sheet transporting means together with the folding roller pair 22.

As shown in FIG. 10A, when the sheet is sandwiched and conveyed by the discharge roller 17b (S4), the folding roller motor 61 stops when the folding rollers 22a and 22b face the second roller surfaces 22a3 and 22b3. (S5, S6). As a result, the folding roller pair 22 does not sandwich the sheet, and the sheet is conveyed by the discharge roller 17b. At this time, the sheet is conveyed by the discharge roller 17b while being guided by the second roller surfaces 22a3 and 22b3 having a small friction coefficient. In this embodiment, whether the sheet is conveyed to the discharge roller 17b and whether the second roller surfaces 22a3 and 22b3 of the folding roller pair face each other are determined by counting the rotation of the motor, but other configurations are used. For example, the seat S may be detected by a sensor, and the drive of the motor may be controlled according to the detection result.

Next, in order to perform the second folding process, as shown in FIG. 10B, the sheet transport is stopped when the rear end E2 of the sheet on which the first folding process has been performed reaches a predetermined position (S7). , S8). Then, the folding roller pair 22 and the discharging roller 17b are reversely driven to execute the switchback transfer process. The sheet rear end E2 is an end portion (hereinafter referred to as "folded end portion") that is folded inside the sheet to be folded by the second folding process when the sheet is folded in three.

Then, when the switchback transfer process is performed, the L-shaped pressing guide member 30 (see FIG. 10B) located at the home position is moved to the rotating shaft 30a as shown in FIG. 11A. While rotating around the seat, the regulation stopper 26 is lowered to move it to the seat receiving position (S9). The folding end portion S2 is pushed downward (in the direction of the seat loading tray 21 where the seat tip S1 is located) by the rotation of the guide member 30. When the discharge roller 17b is reversely driven in this state (S10), the seat S is switched back and conveyed. At this time, the folded end portion S2 of the sheet is guided by the guide surface of the pressing guide member 30 and is conveyed again in the direction in which the regulation stopper 26 of the sheet loading tray 21 is arranged (FIGS. 11A and 11B). reference).

When the first folding position S3 folded by the first folding process after the switchback transfer is started is transferred to the predetermined area (S11), the folding roller motor 67 is driven in the reverse rotation to drive the folding roller pair 22. Is rotated in the reverse direction (S12). As a result, the sheet to be transferred by switchback is also nipped into the folding roller pair 22 and conveyed. The timing for rotating the folding roller pair 22 in the reverse direction is such that when the first folding position S3 passes through the nip portion 22c of the folding roller pair 22, the first roller surfaces 22a2 and 22b2 face each other and the nip portion. The sheet S is controlled to be pressed by 22c (see FIG. 12A). In the present embodiment, the rotation start control is performed by counting the drive pulse of the motor that drives the discharge roller 17b and the like. In this way, when the switchback is conveyed, the first folding position S3 is pressed again by the folding roller pair 22.

After the sheet S to be switchback-conveyed as described above has passed through the nip portion of the discharge roller 17b and the folding roller pair 22, the paddle member 80 is rotated to rotate the sheet loading tray as shown in FIG. 12B. The tip S1 of the sheet S falling in the 21 is scraped off so as to be surely in contact with the regulation stopper 26.

When the seat tip S1 comes into contact with the regulation stopper 26 and the switchback transfer is completed (S13), the drive of the discharge roller motor 68 and the folding roller motor 67 is stopped (S14). Here, the completion of the switchback transfer of the sheet S may be determined by counting the number of drive pulses of the discharge roller motor 68 and the folding roller motor 67 and determining that the sheet S has been conveyed by a predetermined amount.

Next, as shown in FIG. 13 (a), the pressing guide member 30 is rotated to move to the home position (S15), and as shown in FIG. 13 (b), the regulation stopper 26 is raised to raise the seat. The second folding position is moved to a position facing the folding blade 23 (S16). In this state, the cam motor 66 is driven to operate the folding blade 23 again, and as shown in FIG. 14A, the seat S is projected to the nip portion of the folding roller pair 22 (S17).

The folding roller motor 67 and the discharge roller motor 68 are driven in the forward direction in synchronization with the drive of the cam motor 66 (S18). As a result, the sheet S sent to the folding roller pair 22 by the protrusion of the folding blade 23 passes through the nip portion 22c where the first roller surfaces 22a2 and 22b2 face each other, so that the second folding position (second folding position) ) A pressing force is applied to E4, and a second folding process is performed (FIG. 14 (b)).

Then, after the sheet S subjected to the second folding process as described above is nipped by the discharge roller 17b (S20), before the first folding position E3 reaches the nip portion 22c of the folding roller vs. 22. When the second roller surfaces 22a3 and 22b3 of the folding roller pair 22 face each other (S21), the driving of the folding roller motor 67 is stopped (S22). In this state, the sheet S is conveyed by the discharge roller 17b, and the sheet S folded in three is discharged to the loading tray 17c (S23, S24).

As described above, when the second roller surfaces 22a3 and 22b3 face each other, the nip portions 22c of the folding roller pair 22 are in a separated state (here, even if they are separated, the region where the roller surfaces face each other is niped. Department). When the sheet S is conveyed by the discharge roller 17b in this state, as shown in FIGS. 15A and 15B, the first folding position E3 passes through the separated nip portion 22c, so that the first folding position E3 passes through the separated nip portion 22c. No pressing force is applied to the folding position E3 by the folding roller pair 22. As a result, the folding process is not performed again when the first folding position is displaced, so that the folding position is prevented from being displaced or collapsed.

In the present embodiment, as described above, when the sheet subjected to the first folding process is switchback-conveyed, the first folding position E3 passes through the folding roller pair 22. 1 The roller surfaces 22a3 and 22b3 are made to pass through the opposite nip portions 22c. This is because the seat is nipped by at least one of the discharge roller 17b and the folding roller vs. 22 during the switchback transfer from the first folding process, so that the first folding position E3 is unlikely to shift. This is because there is little possibility that the bending will occur even if the pressing force is applied again in the state. On the other hand, after the switchback transfer is completed, the seat S is not in the state of being nipated by the roller pair until the second folding process is executed, so that the first folding process is performed when the second folding process is performed. There is a high possibility that the folding position E3 of the above will be displaced. In that state, if the first folding position E3 is subjected to the same pressing force as in the case of the folding process again by the folding roller pair 22, creases are made in a displaced state, and the folding or folding collapse occurs. ..

In the present embodiment, when there is a possibility that the above-mentioned bending may occur, the first folding position E3 is set to the first folding position so that the second roller surfaces 22a3 and 22b3 pass through the opposite nip portions. On the other hand, since no pressing force is applied, it is possible to prevent bending and the like.

Further, as described above, the second roller surfaces 22a3 and 22b3 are formed of a plastic resin material or the like having a friction coefficient smaller than that of the first roller surfaces 22a2 and 22b2, and the sliding resistance is small with respect to the passing sheet S. .. The nip portions 22c in a state where the second roller surfaces 22a3 and 22b3 face each other are separated from each other with a minute interval through which the folded sheet S can pass. Therefore, the facing second roller surfaces 22a3 and 22b3 function as guide portions for guiding the transfer of the passing sheet, and the folded sheet is guided downstream by the guide portion without hanging down. It is conveyed to the arranged discharge roller 17b.

In the present embodiment, when the first folding position E3 passes through the nip portion 22c, the folding roller pair 22 is maintained in a state where the second roller surfaces 22a3 and 22b3 face each other and the nip portion 22c is separated. However, the rotation of the folding roller pair 22 is stopped so that the first folding position E3 can pass while the nip portion 22c is separated without stopping the rotation of the folding roller pair 22. It may be controlled so as to match the passing timing of the first folding position E3, for example, adjusting the rotation speed of the folding roller pair 22 or adjusting the sheet conveying timing.

Further, in the present embodiment, when the first folding position E3 passes through the folding roller pair 22 after the second folding process, the nip portions 22c are separated from each other so that the pressing force is not applied. Even if the portions 22c are not completely separated, if the pressing force when passing through the nip portion 22c is set to be smaller than the pressing force applied to the first folding process, it is effective in preventing the sheet from collapsing. be.

[Second Embodiment]
Next, a second embodiment for suppressing the occurrence of bending of the first folding position of the sheet will be described. In the above-described embodiment, when the first folding position E3 of the sheet subjected to the first folding process passes through the nip portion 22c of the folding roller pair 22 following the second folding process, the folding roller pair The nip portions 22c of 22 were separated from each other so that the pressing force on the first folding position E3 was adjusted to be lower than that when the first folding process was performed. Then, when the first folding position E3 passes through the nip portion 22c of the folding roller pair when the sheet is switched back and returned to the sheet transport path 20 after the first folding process is executed, the sheet is folded. Assuming that the possibility of deviation or the like is small, the same pressing force as in the first folding process is applied to the first folding position E3 without separating the nip portion 22c.

However, in the present embodiment, at the time of the switchback transport, that is, in order to return the folded sheet that has been folded for the first time to the sheet transport path 20, the first folding position E3 of the sheet S is set to the folding roller pair. The nip portions 22c are configured to be separated from each other so that the second roller surfaces 22a3 and 22b3 of the folding roller vs. 22 face each other even when passing through the nip portion 22c of the 22. It is configured so that the pressing force by the nip portion 22c is not applied to the position E3.

As the control operation, the steps S10 to S12 of the flowchart in FIG. 7 are omitted, and after the first folding process is executed, after the discharge roller 17b sandwiches the sheet, the second roller surface of the folding roller vs. 22 is used. When the 22a3 and 22b3 face each other, the rotation of the folding roller pair 22 is stopped, and in that state, the discharge roller 17b is rotated in the reverse direction to carry out the switchback transfer. Then, after the sheet has passed through the discharge roller 17b, the switchback transfer is completed by dropping the sheet into the sheet transfer path 20 by the rotation of the paddle member 80.

According to the above, the pressing force is not applied when the first folding position E3 passes through the nip portion 22c of the folding roller pair 22 even during the switchback transfer, so that the first folding position E3 is not bent. It is possible to more reliably prevent the occurrence of collapse.

In this case as well, when the first folding position E3 passes through the nip portion 22c, the folding roller pair 22 moves to the first folding position E3 even if the nip portion 22c of the folding roller pair 22 is not completely separated. The same effect can be obtained by adjusting the pressing force to be applied so as to be lower than when the first folding process is performed.

[Third Embodiment]
Next, as a third embodiment, another example of the pressing adjusting means for adjusting the pressing force to the folding position of the sheet will be described. In the above-described embodiment, as a configuration of the pressing adjusting means for reducing the pressing force to the first folding position, the folding rollers 22a and 22b are provided with the second roller surfaces 22a3 having a radius smaller than that of the first roller surfaces 22a2 and 22b2. It is configured to have 22b3 so that the nip portions 22c are separated when the second roller surfaces 22a3 and 22b3 face each other. As a result, the pressing force to the folding position of the sheet can be adjusted depending on whether the nip portion 22c is in pressure contact or separated.

As shown in FIG. 17, the pressing force adjusting means of the present embodiment includes separating means for separating the folding rollers 40a and 40b. Specifically, the folding rollers 40a and 40b are rotatably attached to one end of the arm members 90a and 90b, respectively, and the other end of the arm members 90a and 90b is rotatably attached by a common rotation fulcrum 91. It is supported. The folding rollers 40a and 40b are circular rollers having a constant turning radius, and the folding rollers 40a and 40b are pressed against a sheet that is pressed by a tension spring 92 locked to the arm members 90a and 90b and passes through the roller nip portion 40c. A predetermined pressing force is applied.

On the other hand, an elliptical eccentric cam 93 is rotatably attached to the vicinity of the rotation fulcrum 91 by a motor 94, and pins that can be engaged with the long diameter portion of the eccentric cam 93 are attached to the arm members 90a and 90b, respectively. 95a and 95b are provided. When the eccentric cam 93 is not in contact with the pins 95a and 95b, the folding rollers 40a and 40b are in pressure contact with each other, but when the eccentric cam 93 is rotated, it engages with the pins 95a and 95b and is pushed out. As a result, the arm members 90a and 90b rotate around the rotation fulcrum 91, and the folding rollers 40a and 40b are separated from each other.

Even with the pressing adjusting means having the above configuration, the folding rollers 40a and 40b are separated from each other when the pressing is performed on the first folding position E3 of the sheet in the same manner as in the above-described embodiment. It is possible not to apply the pressing force.

In the configuration of FIG. 17, since the folding rollers 40a and 40b can be formed of circular rollers having a constant turning radius, the pressing force of the folding rollers vs. 40 can be adjusted without using a roller having a special shape. It becomes.

Further, as the pressing force adjusting means, the pressing force may be adjusted without separating the folding rollers 40a and 40b. For example, the folding rollers 40a and 40b are circular rollers having a constant turning radius, but the folding rollers 40a and 40b have a first roller surface having a predetermined hardness (first hardness) in the circumferential direction. It is configured to have a second roller surface made of a material having a hardness lower than the first hardness (second hardness). The folding rollers 40a and 40b are configured to rotate synchronously with the first roller surfaces facing each other and the second roller surfaces facing each other. As the member having the first hardness, silicon rubber, ethylene propylene rubber (EPDM) or the like can be used, and as the member having the second hardness, soft urethane foam or the like can be used.

In the case of the folding roller pair 40 as described above, the folding roller pair 40 is subjected to the first folding treatment on the first roller surface of the folding roller pair 40, and then the first folding treatment is performed. When the processed sheet passes through the nip portion 40c of the folding roller pair 40, the sheet conveying means and the folding roller pair so that the first folding position E3 passes between the second roller surfaces of the folding roller pair 40. Controls the rotation of 40.

For folding roller pairs with different peripheral hardness, the pressing force when the roller surface with low hardness is niping is higher than the pressing force when the roller surface with high hardness is niping with respect to the sheet. It becomes smaller. This makes it possible to prevent the occurrence of folding and folding to the first folding position E3. In such a configuration, it is not necessary to use a roller having a constant turning radius of the folding roller and to provide a configuration in which the folding rollers are separated from each other.

[Fourth Embodiment]
Next, as the fourth embodiment, a configuration in which the pressing force by the folding roller pair can be adjusted according to the rigidity of the sheet to be folded will be described.

As described above, if the folding position of the folded sheet is pressed a plurality of times by the folding roller pair, folding or the like may occur. Therefore, at a folding position where bending may occur, the occurrence of bending can be suppressed by reducing the pressing force of the folding roller pair.

However, when the rigidity of the sheet is high, the folding process is more reliably performed by applying a plurality of pressing forces with the folding roller pair to the folding position. On the other hand, when the rigidity of the sheet is low, creases can be reliably made by pressing once with the folding roller pair.

Therefore, in the present embodiment, the basis weight recognizing means for recognizing the basis weight of the sheet is provided, and when the basis weight of the sheet is equal to or less than a predetermined value, the first folding process of the sheet is performed as described above. The folding position E3 of 1 is adjusted so that the pressing force applied when passing through the nip portion of the folding roller pair following the second folding process is lower than that when the first folding process is performed. This suppresses folding and folding.

However, when the basis weight of the sheet is larger than the predetermined value, that is, when the rigidity of the sheet is larger than the predetermined value, even when the first folding position E3 passes through the folding roller pair a plurality of times, the folding roller pair The pressing force is not reduced, and the same pressing force as in the first folding process is applied. As a result, creases can be reliably made on the highly rigid sheet.

The predetermined value of the basis weight of the sheet is set depending on whether or not the basis weight of the sheet is such that the sheet is creased by one folding process in relation to the pressing force of the folding roller pair. Therefore, the basis weight recognizing means may be one that recognizes by inputting from the input unit according to the type of the sheet.

Similarly, in a configuration in which the folding process is executed in a state where a plurality of sheets are stacked, the rigidity is small when the number of sheets is small, and the rigidity is increased when the number of sheets is large. Therefore, a sheet number recognition means for recognizing the number of sheets when executing the folding process by input or the like is provided, and when the number of sheets is less than or equal to a predetermined number (for example, one sheet), the first folding process of the sheets is performed. The first folding position E3 is adjusted so that the pressing force applied when passing through the nip portion of the folding roller pair again is lower than that when the first folding process is performed. On the other hand, when the number of sheets is larger than the predetermined number (for example, two or more sheets), the pressing force by the folding roller pair is reduced even when the first folding position E3 passes through the folding roller pair a plurality of times. Instead, the same pressing force as in the first folding process may be applied to ensure that the folding process is performed.

A ... Image forming device B ... Sheet processing device B1 ... First processing unit F ... Folding processing device S ... Sheet E1 ... Sheet tip E2 ... Folded end E3 ... First folding position E4 ... Second folding position 17b ... Discharge Roller 20 ... Sheet transport path 21 ... Sheet loading tray 22 ... Folding roller pair 22a, 22b ... Folding roller 22a1,22b1 ... Rotating shaft 22a2,22b2 ... First roller surface 22a3, 22b3 ... Second roller surface 22c ... Nip part 23 ... Folding blade 24 ... Blade carrier 25 ... Cam member 26 ... Regulatory stopper 30 ... Pressing guide member 40 ... Folding roller pair 40a, 40b ... Folding roller 40c ... Roller nip part 60 ... Control unit 100 ... Image forming system

Claims (9)

The sheet is subjected to the first folding process, then the second folding process is performed at a position different from the fold formed by the first folding process, and the sheet folded by the first folding process is performed. In a sheet processing device that performs folding processing so that one end is inside the folded sheet.
A transport path that guides the sheet to be transported in a predetermined transport direction, and
In the transport path, a positioning means for determining a position of the sheet transported to the transport path with respect to the transport direction, and
A pair of rotating bodies that fold the sheet by pressing the sheet conveyed to the transfer path with the nip portion and rotating the sheet.
A protruding member that projects the sheet transported to the transport path toward the nip portion of the pair of rotating bodies, and
A transport means capable of transporting the sheet by switching back in a first direction for pulling in the sheet folded by the pair of rotating bodies and a second direction opposite to the first direction.
A pressing adjusting means for adjusting the pressing force at the nip portion of the pair of rotating bodies, and
The sheet transported to the transport path is subjected to the first folding process by the rotating body pair, the folded sheet subjected to the first folding process is returned to the transport path, and the sheet is returned to the transport path. When the folded sheet is subjected to the second folding process by the rotating body pair, the first folding position of the sheet subjected to the first folding process is the rotation following the second folding process. When passing through the nip portion of the body pair, the positioning means and the rotating body are used in order to reduce the pressing force of the rotating body pair to the first folding position as compared with the case where the first folding process is performed. A pair, a control unit that controls the protruding member, the transporting means, and the pressing adjusting means.
A sheet processing device characterized by being equipped with. The control unit performs the first folding process on the sheet transported to the transport path, and returns the folded sheet that has been subjected to the first folding process to the transport path, so that the first sheet of the sheet is folded. When the first folding position subjected to the folding process passes through the nip portion of the rotating body pair, the pressing force applied by the rotating body pair to the first folding position is applied to the first folding process. The sheet processing apparatus according to claim 1, wherein the rotating body pair, the conveying means, and the pressing adjusting means are controlled so as to be lowered from the time when the rotating body pair is used. In the pressing adjusting means, when the first folding position of the sheet subjected to the first folding process passes through the nip portion of the rotating body pair, the rotating body pair is brought to the first folding position. In order to reduce the pressing force applied to the rotating body pair compared to when the first folding process is performed, the first circumference in which the rotating body pair has a constant radius to the peripheral surface of the rotating body and is in contact with each other at the nip portion to perform the folding process. It has a surface and a second peripheral surface having a radius smaller than the radius of the first peripheral surface and not contacting each other at the nip portion.
In the control unit, the folded sheet obtained by performing the first folding process on the first peripheral surface of the rotating body pair and then performing the first folding process on the rotating body pair is the rotating body. The drive of the transport means and the rotating body pair is controlled so that the first folding position passes between the second peripheral surfaces of the rotating body pair when passing through the nip portion of the pair. The sheet processing apparatus according to claim 1 or 2, wherein the sheet processing apparatus is characterized in that. In the pressing adjusting means, when the first folding position of the sheet subjected to the first folding process passes through the nip portion of the rotating body pair, the rotating body pair is brought to the first folding position. In order to reduce the pressing force applied to the rotating body pair compared to when the first folding process is performed, the first circumference in which the rotating body pair has a constant radius to the peripheral surface of the rotating body and is in contact with each other at the nip portion to perform the folding process. It has a surface and a second peripheral surface made of a material having the same radius as the first peripheral surface and having a hardness lower than that of the first peripheral surface.
In the control unit, the folded sheet obtained by performing the first folding process on the first peripheral surface of the rotating body pair and then performing the first folding process on the rotating body pair is the rotating body. Controlling the transport means and the rotating body pair so that the first folding position passes between the second peripheral surfaces of the rotating body pair when passing through the pair of nip portions. The sheet processing apparatus according to claim 1 or 2. The pressing adjusting means has a separating means for pulling away the contact at the nip portion of the rotating body pair.
When the first folding position where the first folding process is performed passes through the nip portion of the rotating body pair after the first folding process is performed by the rotating body pair, the control unit performs the first folding process. The sheet processing apparatus according to claim 1 or 2, wherein the transport means, the rotating body pair, and the separating means are controlled so as to separate the contact of the rotating body pair. The second peripheral surface of the rotating body pair has a guide portion for guiding the seat.
The third aspect of claim 3, wherein the control unit controls the drive of the pair of rotating bodies so as to be guided by the guide unit when the sheet passes between the second peripheral surfaces. Sheet processing equipment. Further provided with a basis weight recognizing means for recognizing the basis weight of the sheet, when the basis weight recognized by the basis weight recognition means is equal to or less than a predetermined value.
In the control unit, when the first folding position of the sheet subjected to the first folding process passes through the nip portion of the rotating body following the second folding process, the rotating body pair In order to lower the pressing force applied to the first folding position than when the first folding process is performed, the positioning means, the rotating body pair, the protruding member, the conveying means, and the pressing adjustment The sheet processing apparatus according to any one of claims 1 to 6, wherein the means is controlled. When the number of sheets recognizing means for recognizing the number of sheets is further provided and the number of sheets recognized by the number recognizing means is equal to or less than a predetermined value,
In the control unit, when the first folding position of the sheet subjected to the first folding process passes through the nip portion of the rotating body following the second folding process, the rotating body pair In order to lower the pressing force applied to the first folding position than when the first folding process is performed, the positioning means, the rotating body pair, the protruding member, the conveying means, and the pressing adjustment The sheet processing apparatus according to any one of claims 1 to 6, wherein the means is controlled. An image forming device that forms an image on a sheet,
A sheet processing device that folds a sheet sent from the image forming device, and a sheet processing device.
Have,
The image forming system, wherein the sheet processing apparatus is the sheet processing apparatus according to any one of claims 1 to 8.

Images